Degradation of polypropylene under the effect of the low-molecular-mass organic peroxides below the melting temperature of the polymer

The efficiency of five commercially available peroxides on the level of degradation of polypropylene (PP) at temperatures below its melting point has been studied. The efficiency extrapolated onto 100 degrees C increases in the following order: tert. butylperoxy-2-ethyl-hexanoate approximate to tert. butylperoxy-isobutyrate < dilauroyl peroxide < 1,1-bis(tert. butylperoxy)-3,3,5-trimethyl cyclohexane approximate to tert, butyl-perbenzoate. The various effects of peroxides on the degradation of PP is explained by different reactivity of primary radicals of the peroxides and their solubility.